Multiaxle drive vehicle



Feb. 1, 1938. A. w. HERRINGTON MULTIAXLE DRIVE VEHICLE Filed Dec. 5, 1936 5 Sheets-Sheet l dil /I. uh aln-b iom ATTORNEYS.

Feb. 1, 1938. w HERRINGTQN 2,107,072

MULTIAXLE DRIVE VEHI OLE Filed Dec. 5, 1936 5 Sheets-Sheet 2 INVENTOR. APE AH)- Xflem-in Zon. HY

T ORNEYJ.

Feb. 1, 1938. w HERRINGTQN 2,107,072

MULTIAXLE DRIVE VEHICLE Filed Dec. 5, 1936 3 Sheets-Sheet 3 IN VEN TOR.

Wu-0d v ATTORNEYS,

Patented Feb. 1, 1938 UNITED STATES PATENT OFFICE MUL'I'IAXLE DRIVE VEHICLE Application December 5, 1936, Serial No. 114,371

2 Claims.

The usual motor vehicle comprises a chassis frame supported at its front andrear ends upon axles which are in turn supported by wheels journalled upon the outer ends of the axles, and the vehicle is guided by swinging each of the front wheels about a. substantially vertical axis.

When such a vehicle is propelled through an arc-shaped path the front wheels always traverse longer paths than the rear wheels and each outer wheel of each pair traverses a longer path than its companion inner wheel. The last-mentioned differential is compensated, as to wheel pairs to which power is applied, by one of many well known forms of difierential gearing and the firstmentioned differential, as to non-powered wheels, is of no consequence.

In vehicleswhere more than one pair of powered traction wheels are provided, however, as in four-wheel drive structures, the firstmentioned distance differential becomes a nonnegligible factor which results in undue wear of the front wheel tires and an unnecessary consumption of power which cannot be compensated by the usual differential gears interposed between the power source and the transverse pairs of traction wheels.

The object of my invention is to provide mechanism by means of which delivery of power to the front power-driven wheel which will be automatically discontinued during arcuate travel and automatically resumed upon resumption of straight-line travel; together with manually manipulable means for temporarily rendering said automatic means non-effective, and, in one form, manually-manipulable means for temporarily disconnecting the front power-driven wheels from the motor.

The accompanying drawings illustrate my invention.

Fig. l is a diagrammatic elevation of a. fourwheel drive vehicle embodying my invention;

Fig. 2 a diagrammatic plan;

Fig. 3 a medial vertical section of a speedchange gear train embodying my invention;

Fig. 4 a transverse section on line 4-4 of Fig. l; and

Fig. 5 a section on line 55 of Fig. 4.

In the drawings Ill indicates the chassis frame, II, II, the rear driven wheels, l2 the rear axle structure, l3, l3 the front power-driven wheels, each swingable about a subtantially vertical axis and controlled by steering means including the usual steering wheel 14. Each of the axles, where all the traction wheels are of the same diameter, embodies power-delivery means including a differential gearing. All of these parts may be of well known form although I prefer that the differential in the front axle be laterally offset to one side of the medial line of the vehicle for a reason which will appear. 5

The motor l5 will be connected through the usual clutch l6 and primary speed-change gearing I! to the power-receiving shaft of the mechanism now to be described.

Journalled in housing 20 is the power-receiving shaft 2| connected by universal coupling 22 with the power-delivery shaft 23 of the primary speedchange gearing I'I. Allned with shaft 2| is the power-delivery shaft 24 upon the outer end of which is splined the sleeve 25 of a universal coupling 26 which is connected by shaft 21 with the differential of the rear axle.

Shaft 24, at its inner end, is provided with a spur gear 28, and an internal clutch-tooth series 29 adapted to receive the external spur gear 30 2o splined on shaft 2|. Gear 30 is shiftable into and out of clutching relation with shaft 24 and, through a non-active intermediate position, out of and into mesh with a gear 3| carried by counter-shaft 32 journalled in housing 20, gear 3| being of larger diameter than gear 30.

Also carried by shaft 32 and rotating with gear 3I- is a gear 33.

Also journalled in housing 20 is the powerdelivery shaft 34 which is connected by universal coupling 31 with the shaft 36 which leads to the differential of the front axle.

Journalled on shaft 34 is a gear 35 which meshes with gear 33.

In the present drawings the ratio of gears 28-35 is 1 to 1 because of the provision of endless track (to be described later) instead of ground wheels of the same size as the driven front-wheels, and it will be readily understood that, if rear ground wheels be provided, gears 28 and 35 will be of equal size.

Between gear 35 and shaft 34 I interpose an overrunning clutching means C which may be any one of a number of acceptable efllcient form so long as it permits shaft 34 to overrun gear 35 when the vehicle is pursuing an arcuate course.

In the present instance I have illustrated an overrunning clutch of the helical spring type wherein the helical spring 40, coaxial with shaft 34, is non-rotatively anchored at one end by collar 4| on a sleeve 42 journalled on shaft 34 with the external periphery of sleeve 42 of such diameter that, upon slight angular movement of the free end of the helix, said helix will become frlctionally locked with gear 35. The free end 55 II and shaft 34 is insured by a collar 43 sleeved within said helix 40' and splined on sleeve 42. With this form of compound helix the external dimeter of portion 4. is such that normally, with said portion 40 not expanded, there is little, if

' any, frictional contact with bore 35'.

At one end, sleeve 42 is provided with an external cylindrical series of clutch teeth 44 overlaid by an internal cylindrical series of clutch teeth 45 carried by gear 38. Splined upon shaft 34 is a clutch ring 44 provided with a cylindrical series of clutch teeth 41 adapted to interlock with teeth 45 and an internal series of clutch teeth 44 interlocking continuously with the splines 48 of shaft 34 and capable of interlocking with teeth 44 either with or without interlocking with teeth 4!.

Clutch ring 4' is manually shiftable to any one oi. its three positions by means of an axially shiftable rod SI and yoke 5|, rod 54 being connected to a suitable shifting lever (not shown) arranged within easy reach of the driver of the vehicle in any well known manner.

Gear 30, which in one position serves as a clutch ring, is manually axially shiftable by means of a rod 52 and yoke 54, rod 52 being connected to a suitable shifting lever (not shown) arranged within easy reach of the driver of the vehicle in any well known manner.

The casing 24 depends from the axis of shafts 2| and 24 at an angle of about 45 degrees (not critical) and, at its lower end, is braced by a cushioned brace 65 anchored on the chassis frame.

The above described mechanism within housing Ill providw a two-speed selective gear ratio between the primary usual speed changing gearing [1 and the front and rear traction means, wherein one speed ratio is obtained when gear 30, as a clutch element, engages teeth 29 and the other speed ratio is obtained when gear ill is in mesh with gear 3|.

In addition, that portion of the mechanism within housing 20 comprising parts 45, 40, 4|,

. 4|, 4!, 44, 45, 46, 41, 48, 49, whereby shaft 34 is entirely segregated from the motor (ring 46 being in the position shown in Fig. 5); or shaft 34 is connected to the motor through the medium of the overrunning clutch C (ring 48 being in mesh with teeth 44 but not in mesh with teeth 45) or shaft 34 is directly connected to gear 35 and the overrunnlng clutch C is rendered ineffective (ring 48 being in mesh with teeth 44 and 4!),

permits the driver to manually determine whether the propeller shaft 38 shall be positively driven in synchronism with propeller shaft 21, or shall be permitted to temporarily overrun shaft 21, or shall be entirely disconnected from the motor though shaft 21 is connected. It will be noted in this connection that any temporary overrunnlng of shaft 38 relative to shaft 21 resulting from a functioning of the overrunnlng clutch will be entirely noiseless.

It will be noticed that, in the drawings, the rear driven wheels I2 are not traction wheels, as they well might be without altering the operation of the various parts described above, but are the driving wheels each for an endless traction belt or track 60 engaging therewith and also supported each by an end idler II with intermediate idlers 42, 62, I, 63 interposed between the lower run of the track and the chassis frame.

In the illustrated embodiment of this feature, the two idlers 62, 82 are journalled at opposite ends of a beam 64 pivoted at 65 upon the forward end of an arm 66 pivoted at 01 on bracket 48 depending from the chassis frame. Similarly idlers Cl, 64 are journalled on beam 84' pivoted on rearwardly extending arm 66' pivoted at 81'. An

I equalizer lever 69, pivoted at III on bracket '4 overlies arms 66 and 68' to receive the upward thrust of each arm and transmit it as a downward thrust on the companion arm.

In order that the peripheral speed of the traction tracks may be equal to that of the front wheels-in straight line travel-the diameters of the gears 28 and 35 are properly proportioned.

I claim as my invention:

1. A power-transmission unit for motor vehicles,

comprising a casing, a shaft journalled therein 'and projected from one side thereof and adapted from the opposite side of the casing and adapted for connection with the vehicle propeller shaft, a manually controlled clutch interposed between said aligned shafts, a third shaft journalled in the casing and projected from one side thereof and adapted for connection to a second propeller shaft, a power-transmission train interposed between said first and third shafts and comprising an overrunning clutch, a manually shiftable clutching element interposed between said overrunnlng clutch and said third shaft and selectively shiftable to segregate said third shaft from the power-transmission train or to connect said third shaft with the power-transmission train through the overrunnlng clutch, or to connect the powertransmission train with said third shaft independent of said overrunnlng clutch.

2. Apparatus of the character specified in claim 1 wherein the power-transmission train is of a selective speed type, selectively dependent upon the position of the first-mentioned clutching element.

ARTHUR W. HERRINGTON. 

